zeroToOne
ENDEPL
Start a scope
Sec.01 — Mandate

Software built to the shape of your operation.

zeroToOne is a senior engineering studio. We model how your business actually runs, then build the systems that run it — scoped in days, deployed in weeks, transferred to you in full.

Start a scope Review deployments
Fig.01 — Domain ontologylive
Engagement
6–12 wks
typical duration
Team
2–4
senior engineers, no juniors
First deploy
Week 1
production, not a prototype
Ownership
100%
repository transferred to you
Sec.02 — Capabilities

One team accountable end to end.

Strategy, design, engineering and the infrastructure underneath, delivered by the same people who scoped the work. Pick a single capability or the full stack.

RefCapabilityDefinitionPrimary tooling
SVC.01

Domain modelling

We map the entities, rules and edge cases your business runs on before any code is written.

workshopsschemadecision log
SVC.01 · Capability

Domain modelling

Two to five days with the people who actually do the work — not only the people who describe it. We leave with one written model everyone has agreed to, and a list of the questions nobody could answer yet.

What you get
  • Written domain model
  • Entity and rule catalogue
  • Decision log with named owners
  • Open questions, ranked by cost
You need this when
  • Two teams mean different things by the same word
  • Every new feature needs an exception
  • The spec keeps growing and never converges
Primary tooling
workshopsschemadecision log
SVC.02

Product engineering

Full-stack delivery, including the unglamorous parts — auth, billing, migrations, backfills.

TypeScriptPostgresReact
SVC.02 · Capability

Product engineering

We build and run the whole thing, including the parts that never make a screenshot. The system goes to production early and stays there, so problems surface while they are still cheap.

What you get
  • Production system on your infrastructure
  • Test suite and CI pipeline
  • Runbook and on-call notes
  • Repository transferred to you
You need this when
  • Version one has been in the backlog for two quarters
  • You are hiring for a team you do not have yet
  • The prototype cannot carry real load
Primary tooling
TypeScriptPostgresReact
SVC.03

Data & AI systems

Retrieval, agents and structured extraction with evaluations, guardrails and latency budgets attached.

evalsRAGtracing
SVC.03 · Capability

Data & AI systems

Anything with a model in it needs a way to tell whether it got better. We build the evaluation harness first, then the pipeline, so quality is a number rather than an opinion.

What you get
  • Evaluation harness with a scored set
  • Retrieval or agent pipeline
  • Tracing and cost dashboards
  • Guardrails and fallback paths
You need this when
  • The demo worked and the tenth case did not
  • Nobody can say whether a change improved anything
  • Costs move and no one knows why
Primary tooling
evalsRAGtracing
SVC.04

Platform & infrastructure

Migration, infrastructure-as-code, CI/CD and telemetry your own team can operate unaided.

TerraformCI/CDOTel
SVC.04 · Capability

Platform & infrastructure

Infrastructure your own team can operate after we go. Everything is code, everything is reproducible, and the handover is a workshop rather than a document.

What you get
  • Infrastructure as code
  • CI/CD with a tested rollback
  • Metrics, logs and traces
  • Handover workshop with your team
You need this when
  • Deploys happen when one particular person is free
  • Nobody knows what production actually costs
  • Staging and production have drifted apart
Primary tooling
TerraformCI/CDOTel
SVC.05

Security & assurance

Threat modelling, access design and audit trails built into delivery, not bolted on before launch.

SSORBACaudit
SVC.05 · Capability

Security & assurance

Access design and audit trails belong in the model, not in a document written the week before a review. We build them in and give you the evidence you will be asked for.

What you get
  • Threat model for the real system
  • Role and access design
  • Audit trail across all mutations
  • Remediation plan, ranked by risk
You need this when
  • A customer sent a security questionnaire
  • Access is granted by asking someone nicely
  • You cannot show who changed a record
Primary tooling
SSORBACaudit
Sec.03 — Models

Three ways to deploy us.

The engagement adapts to where you are. The people do not change between models.

Model A

Embedded

One to three of our engineers inside your repositories and your standups, for a quarter or longer.

  • Your stack
  • Your rituals
  • Monthly review
Model A

Embedded

For teams that already have a direction and need senior capacity that does not require managing. We work in your repositories, your tools and your cadence.

What is included
  • One to three senior engineers
  • Your stack, your process
  • Written review every month
  • Notice period, not a lock-in
Commercials

Monthly rate per engineer, rolling, with one month of notice.

Model B

Dedicated build

A ring-fenced team delivering a defined system end to end against a fixed scope and a fixed price.

  • Written scope
  • Weekly demo
  • Fixed price
Model B

Dedicated build

For a defined system with a real deadline. The scope is written down before anyone starts, and the price follows the scope rather than the hours.

What is included
  • Written scope agreed before work starts
  • Weekly demo on real infrastructure
  • Fixed price against that scope
  • Change requests quoted separately
Commercials

Fixed price, released by milestone. Scope changes are quoted, never absorbed quietly.

Model C

Founding build

Your first engineering team. We build version one and transfer it when you are ready to hire.

  • 0 → 1
  • Full transfer
  • 30-day support
Model C

Founding build

For founders without an engineering team yet. We build version one, run it in production, and hand it over in a state your first hires can pick up.

What is included
  • Version one in production
  • Documentation and recorded walkthroughs
  • Repository and infrastructure transfer
  • Thirty days of support after handover
Commercials

Fixed price per phase. Transfer is included, not an upsell.

Sec.04 — Timeline

Scoped in days. Deployed in weeks.

A standard engagement, plotted by week. Phases overlap because delivery does.

0
1
2
3
4
5
6
7
8
9
10
11+
P1 · Scope
P2 · Build core
P3 · Harden
P4 · Transfer
P1 · Scope

Domain workshops and a written specification. Fixed price and deliverables agreed before any code is written.

P1 · Scope

Scope

Domain workshops and a written specification. Fixed price and deliverables agreed before any code is written.

What you get
  • Domain model, written and signed off
  • Scope and fixed price
  • Risk and open-question log
What we need from you

Two to five days of your team's time, and access to whoever knows the exceptions.

P2 · Build core

The critical path in production from week one. Weekly demos against the scope, on real infrastructure.

P2 · Build core

Build core

The critical path in production from week one. Weekly demos against the scope, on real infrastructure.

What you get
  • Critical path running in production
  • Weekly demo against the scope
  • Infrastructure as code
What we need from you

An hour a week at the demo, and decisions when we ask for them.

P3 · Harden

Edge cases, performance, access control, migration of real data, and the telemetry to see all of it.

P3 · Harden

Harden

Edge cases, performance, access control, migration of real data, and the telemetry to see all of it.

What you get
  • Edge cases and performance work
  • Access control and audit trail
  • Real data migrated and reconciled
What we need from you

Real data, real users, and someone who can sign off the migration.

P4 · Transfer

Documentation, recorded walkthroughs, repository transfer and thirty days of support after launch.

P4 · Transfer

Transfer

Documentation, recorded walkthroughs, repository transfer and thirty days of support after launch.

What you get
  • Documentation and recorded walkthroughs
  • Repository and infrastructure transfer
  • Thirty days of support
What we need from you

Whoever will own the system after us, in the room for the walkthroughs.

Sec.05 — Method

Most failed projects were mis-modelled, not mis-coded.

The expensive mistakes happen before the first commit — in the entity nobody defined, the rule only one person knew, the exception that turns out to be half the volume. No amount of engineering recovers from that cheaply.

So we start by modelling the domain: what things exist, how they relate, which rules are real and which are habit. The build follows from that model, and so does everything you extend after we leave.

01
Model before code

Two to five days of workshops produce a written domain model you sign off.

02
Deploy before polish

The core path runs in production in week one, so decisions meet reality early.

03
Transfer by default

Everything is written to be handed over, from commit one — not documented at the end.

Fig.02 — Modelling passschematic
SYSTEMSwhat exists todayPEOPLEwho decides whatRULESreal vs. habitualDOMAIN MODELthe shared spineINTERFACESwhat users touchAUTOMATIONwhat runs itself

Open details

Sec.06 — Deployments

Selected systems in production.

Detailed write-ups available under mutual NDA.

DEP.01Manufacturing

B2B ordering platform

A factory's catalogue, contract pricing and live stock exposed to partner shops through a portal and a versioned API. Orders arrive priced and validated instead of as email attachments retyped by hand.

−80%manual order entry
DEP.01 · Manufacturing

B2B ordering platform

The problem

Partner shops ordered by email and phone. Every order was retyped by hand, prices came from a spreadsheet that was already out of date, and nobody could say what was actually in stock.

What we built

A portal and a versioned API over the factory's real catalogue, contract pricing and live stock. Orders are priced and validated at the point of entry, and confirmed availability is returned immediately.

Outcome

Order handling stopped scaling with headcount. Partners self-serve, the order desk handles exceptions instead of transcription, and pricing errors from stale spreadsheets disappeared.

Stack
Next.jsPostgresREST APISSO
DEP.02Home furnishings

ERP for a furniture factory

Production, stock, costing and orders on one domain model built around how the plant actually runs. Per-order costing they can trust let them hold margin against low-cost imports instead of guessing at it.

6 → 1systems replaced
DEP.02 · Home furnishings

ERP for a furniture factory

The problem

Cheap imports were setting the price the market expected. Without a trustworthy cost per order, the factory could not tell which products still made money and which were being subsidised by the rest.

What we built

Production, stock, costing and orders on a single domain model built around how the plant actually runs — including the routing exceptions that six separate tools had each recorded differently.

Outcome

Costing became something to decide with rather than argue about. Margin is defended per product line on real numbers, and six tools collapsed into one system the team operates itself.

Stack
TypeScriptPostgresEvent logReporting
DEP.03Forestry & timber

FSC chain of custody

Stock, consumption and purchases tracked per certified batch, so the input-output balance holds up under audit. Certification becomes a by-product of daily work rather than a quarterly scramble.

0audit non-conformities
DEP.03 · Forestry & timber

FSC chain of custody

The problem

Certified and uncertified material shared the same yard and the same machines. The input-output balance was reconstructed by hand before every audit, from delivery notes and memory.

What we built

Stock, consumption and purchases tracked per certified batch, from goods-in to finished product, with the balance computed continuously and exports in the format the auditor asks for.

Outcome

Certification stopped being a quarterly scramble. The balance is correct on any given day, and the evidence for it is a report rather than a week of work.

Stack
TypeScriptPostgresBatch trackingExports

“After rolling out the system zeroToOne built for us, we increased production throughput by over 50% — without adding a single machine.”

Miroslav — CEO, Furniture Factory
Sec.07 — Contact

Tell us what you need built.

A 45-minute call. Bring the problem, not a specification. You leave with our honest read on what to build, how long it takes and what it costs — whether or not you use us.

contact@zt1.io
Sec.07 — Intro call · 30 minOpen in new tab ↗